As to your conclusion, there are guys in prison today for violations of the exact same laws, and several are now attempting to appeal their sentences. At the time they were convicted, those laws were seen as strict liability, so their trial records do not include proof of intent. If those same laws, which haven't changed, require mens rea now, at the very least they need a retrial to establish intent.
Can you please name a couple of these guys? I don't know who you are referring to.
Also, I'm confused about what you said about 'intent'. Are you saying that these guys did not have intent, or simply that the government did not have prove it? It would seem that the recommendation to prosecute or not (by Comey?) would partly depend on that.